For the best part of three rounds, Kirkland did what Kirkland does: churned forward, fired punches, and looked to inflict hurt. And for the best part of three rounds, Alvarez, ice to Kirkland's fire, withstood that assault and responded calmly but effectively in kind. The he steered his foe to the ropes and uncorked a perfect overhand right that rendered Kirkland unconscious the moment it landed before sending him spinning until he landed flat on his back. Kirkland, as is his wont, was swinging for the fences even as the conclusive, concussive blow landed.

Eric Raskin: Canelo Alvarez KO 3 James Kirkland

In few settings is it appropriate to celebrate bodies going limp and crashing to the ground in grotesque fashion. But in boxing, that is to a certain extent the very point of the exercise. And there was no physical collapse in 2015 more aesthetically perfect, more poetic, than the lifeless pirouette Kirkland involuntarily performed after Canelo rocketed a right hand directly into his jaw in the third round of their May battle. The blood from Kirkland's mouth splattered across him as he spiraled downward, and by the time his body reached the canvas, the fight was over.

Nat Gottlieb: Canelo Alvarez KO 3 James Kirkland

It's hard to imagine any KO this year that can match Canelo's left hand to the body of Kirkland, followed by a perfect right hand to the jaw that literally corkscrewed Kirkland into the canvas. That camera shot of Canelo walking away from the fallen Kirkland and climbing up the turnbuckle in victory as the referee attended to Kirkland was a masterpiece.

Oliver Goldstein: Canelo Alvarez KO 3 James Kirkland

Not necessarily an all-time classic — there's a mysterious uniformity that ties the best knockouts together, something in the way the knocked out fighter falls that brings them together — but this was pretty sweet all the same. Canelo had beat on James Kirkland through three rounds, variously looking several levels above him. Then, as Kirkland flailed on the ropes, Canelo ended things, cracking Kirkland with a straight right that landed just as the Texas fighter missed with a wild one. The shot left Kirkland spinning like a table top, before thudding face-first to the canvas. That was that.

Diego Morilla: Francisco Vargas TKO9 Takashi Miura

It's may not be the one-punch-and-you're-out knockout that makes headlines and stays in the minds of fans and press alike at the year-end polls. If it helps, I'll label it the "stoppage of the year" and leave it at that. But just the fact that Vargas was able to come back from the verge of an embarrassing and potentially career-wrecking early knockout to take out a Japanese warrior who was willing to fight on one wobbly leg in that made-for-Hollywood ninth round is enough for me. It was an undercard bout between two proven fighters who were expected to deliver a tasty appetizer and ended up serving the main course in an already great boxing banquet.

Harold Lederman: Canelo Alvarez KO 3 James Kirkland

Carlos Acevedo: Canelo Alvarez KO 3 James Kirkland

James Kirkland may have been slightly faded when he faced Saul Alvarez in May, but he still set a relentless pace in hopes of ending things early. Unfortunately, Kirkland has always had a bad habit of squaring up and dropping his hands, so when Alvarez maneuvered him into the ropes in the third round, Kirkland, who had already been down twice earlier in the fight, was an open target. After throwing a decoy left to the body, which made Kirkland lower his guard, Alvarez launched an overhand right that left Kirkland sprawled on the canvas, oblivious to the roar of thousands at Minute Maid Park in Houston.

It was an upset in many people's eyes and it came from the most unlikely source. Postol actually made Matthysse quit.

Frank Della Femina: Canelo Alvarez KO 3 James Kirkland

Canelo's finishing punch on James Kirkland in the third round of their May fight was without a doubt the KO of the Year. By that point in the fight Kirkland was in trouble and, after having already hit the canvas twice on the night, landed for that third and final time when Canelo dropped the curtain with a heavy right hand. It was lights out for Kirkland. To Canelo's credit, he did say afterward that he was concerned for Kirkland's well-being. Kirkland on the other hand had no memory of being floored. Brutal KO.

Frank Miller: Canelo Alvarez KO 3 James Kirkland

As James Kirkland lay on the canvas, a clearly distraught Canelo Alvarez hovered over doctors to check Kirkland's condition. Alvarez's face says everything necessary for why this fight wins Knockout of the Year. Clearly Canelo is surprised by the extent of his own power. Following his post-fight interview with Max Kellerman he hugs Kirkland and says: "You OK? I have respect for you." So will every single person who ever watches that fight.

Michael Gluckstadt: Canelo Alvarez KO 3 James Kirkland

If you saw Canelo-Kirkland in a movie, you'd say it was unrealistic. Too much action up front, too cinematic a final fall – not plausible. That's not how boxing really looks, the sport's Comic Book Guys would say. You couldn't have choreographed it better if you tried.